MySQL evangelist here ;-), for any cluster/HA solution relying on multiple machines linked by a network, if you can't rely on the network, it's very complicated to rely on the solution. This is valid for MySQL InnoDB Cluster but for any other quorum based solution.
The third point of the requirements is Network Performance (https://dev.mysql.com/doc/refman/8.0/en/group-replication-re...) maybe we should add "and Reliability"
Of course as you may have noticed, 8.0.16 already brings new features helping with a flaky network and even if we will never encourage people to deploy MySQL InnoDB Cluster (Group Replication) on a bad network, we are constantly working on improving the user experience even on such environment.